Anyone in the US using an unlocked international version?

I'm curious if anyone in the US is using an unlocked international version of the phone. I'm on AT&T and I bought the AT&T version of the phone but ended up returning it because I couldn't stand all of the extra crap that was added to the phone. I'm seeing brand new unlocked phones selling on ebay for low 600s and I'm thinking of going this route. I know that Samsung Pay won't work (which I don't really care about since my bank doesn't support it anyway) but are there any other quirks that I should expect?

I have not used a carrier phone before so cant say what you may miss.
1) The phone can be used on AT&T and I get proper 4G LTE connection.
2) Phone is going to have an exynos processor with Samsung/Sony camera sensor, in any case from what I have read and seen, Exynos with Samsung sensor is better in terms of Speed, Battery Life & image quality(debatable however).
3) No warranty so you need to purchase one
4) Charger would need an adapter.